Besides the searches for angular correlations, also the detailed study of the energy distribution of the neutrinos should give important information about the mechanism producing the neutrinos, and hence on the nature of the CR sources. However, analyses using different neutrino datasets (muon tracks [1]}, cascade events [2]} or high energy starting events [3]}) don't lead to a definite picture about the astrophysical neutrino spectral shape. In particular, the slope \(\gamma \)  of a power-law fit \(\phi _\nu \propto E_\nu ^{-\gamma }\)  which is obtained from the different studies actually covering the range of values between 2 and 3, so that more data would be required in order to clarify this issue.
